Question

Find the area of AABC, given that
(i) AB = BC = 10 cm, ZABC = 90°
(ii) BC = CA = 6 cm, ZBCA = 90°
(iii) CA = 9 cm, ZABC = ZBCA = 45°​

Answer 1

Step-by-step explanation:

Given:

∠BDC=90

∘

∠ABC=90

∘

Let ∠BCD=x

∘

Using triangle sum property in △BDC, ∠DBC=90−x

∘

Also ∠ABD=x

∘

Using triangle sum property in △ADB, ∠BAD=90−x

∘

Now considering △BDC and △ADB

∠BDC=∠BDA [∵∠BDC=∠BDA=90

∘

]

∠DBC=∠DAB [∵∠DBC=∠DAB=(90−x)

∘

]

So by AA

△BDC∼△ADB

Hence

CD

BD

=

BD

AD

CD

8

=

8

4

CD=16

Hence CD=16cm